Webs of materials are commonly produced on production lines in which the end step of the production line is to wrap the web of material onto a core in a winding operation. The core can be supported by a core shaft that is rotatably mounted at the end of the production line. An example of such a web of material wound on a core tube can be thought of as being much like the way in which a web of paper towel material or toilet paper is wound on a cardboard core.
In producing webs of materials in commercial quantities, the mass of web wound on a core can greatly exceed the mass that manufacturing line workers can handle easily. For instance, webs can have a width of several meters and tens of meters of material can be wound about a core. If the web material is something of the nature of household carpet or field turf, the mass can be over one-thousand kilograms. Even for webs commonly thought of as being lightweight materials, such as paper, toilet paper, paper towel material, or absorbent webs for sanitary articles, the mass of the web wound on the core at the end of a production line can exceed one-hundred kilograms.
On a production line, once the desired quantity of the web of material is wound on the core, the web material is cut from web of material upstream of the winding operation. The core shaft, which supports the core, can be moved to a position in which the wound core can be removed from the production line and taken to another production line in which the web of material is integrated into another product, altered further towards the ultimate commercial embodiment, or prepared for storage and/or shipping. Then the core shaft is removed from within the core or the core is removed from the core shaft and the core shaft is moved to a position in which the core shaft can be used again to support another empty core that is subsequently wound with a web.
One approach for removing a core shaft is to support the core shaft, core, and web of material by supporting the web of material by the outer plies whereby the mass of the web is relieved from resting on the core shaft and the core shaft and core can relatively easily slide with respect to one another. For sensitive materials, such as tissue webs and thin porous foams, stress applied to the outer plies of the web wound on the core to relieve the stress between the core shaft and core can damage the web material. Furthermore, applying stress axially to the web to force the web and core to slide off of the core shaft can damage the web of material.
One approach to removing the core shaft from a loaded core without stressing the web material is to support the loaded core shaft at each end of the core shaft, connect an axial support to one end of the core shaft, remove the support at the end of the core shaft proximal the axial support, slide the loaded core onto the axial support, replace the support at the end of the core shaft proximal the axial support, separate the axial support from the core shaft, connect an axial support loaded with an empty core to one end of the core shaft, remove the support at the end of the core shaft proximal the axial support, slide the core onto the core shaft, replace the support at the end of the core shaft proximal the axial support, and moving the core shaft and empty core from the supports into a position in which the core shaft can be used again to support another empty core that is subsequently wound with a web. One drawback to such an approach is that many steps of supporting and removing support from the core shaft are required, thus increasing the time required to remove a core shaft from a loaded core and increasing the possibility of the loaded core falling, thereby damaging the web material.
With these limitations in mind, there is a continuing unaddressed need for a method for removing a core shaft from a loaded core in a simple and time-efficient manner that will not damage web material. There is a further continuing unaddressed need for a method for removing a core shaft from a loaded core that provides for a simple process for providing a fresh core on core shaft.